“Agreeing to disagree” type results: a decision-theoretic approach

This paper explores interactive epistemology within Morris’ S. Morris, Alternative definitions of knowledge, in: M.O.L. Bacharach, L.-A. Gerard-Varet, P. Mongin, H.S. Shin (Eds.), Epistemic Logic and the Theory of Games and Decisions, Kluwer Academic Publishers, Amsterdam, 1997, pp. 217–233] framework of knowledge. Specifically, this paper proves a generalized “agreeing to disagree” result. The major features of this formalization are: (i) non-expected utility receives a unified treatment; (ii) the information structure is not necessarily partitional; (iii) Aumann’s celebrated result of “agreeing to disagree” and Milgrom and Stokey’s well-known result of “no trade” are derived as special cases. This paper also presents some new extensions of the “no trade theorem”.